In a fluid circuit, such as a refrigerant circuit of a vapour compression system, it is sometimes desirable to split the flow path into two or more parallel flow paths along part of the fluid circuit. This is, e.g., the case in vapour compression systems comprising two or more evaporators arranged in parallel. It may further be desirable to be able to control the fluid flow to each of the parallel flow paths, e.g. in such a manner that a substantially equal fluid distribution is obtained, or in such a manner that the system is operated in an optimum manner, e.g. in terms of energy consumption or efficiency.
In some previous attempts to control distribution of refrigerant between two or more parallel flow paths in a vapour compression system, a distributor is arranged downstream relative to an expansion valve in the refrigerant flow path. Thus, the refrigerant is distributed after expansion of the refrigerant, i.e. the refrigerant is mainly gaseous. This has the disadvantage that it is very difficult to control the flow of refrigerant to obtain a substantially equal distribution between the parallel flow paths.
In other previous attempts to control distribution of refrigerant between two or more parallel flow paths in a vapour compression system, a single inlet opening is moved between two or more outlet openings, each outlet opening being fluidly connected to one of the parallel flow paths, in such a manner that fluid medium is sequentially supplied to the parallel flow paths, via the inlet opening and the corresponding outlet opening. Thereby fluid medium is supplied to a given flow path only when the inlet opening is arranged at a position where it establishes a fluid connection to the outlet opening corresponding to the given flow path. Furthermore, when the inlet opening is arranged in a position where it establishes a fluid connection to a given flow path, none of the remaining flow path(s) receives fluid medium. This may result in the fluid flow delivered to the flow paths being relatively uneven.